Find some poles, around 5 ft long, half to an inch thick. Trim to the same height. Arrange as a teepee ("wigwam"), secure with string. Now weave an open framework to create an obelisk. You may care to use some rustic twine for any final binding.
Looks great with things growing up it. Sweet Peas? Beans? Looks pretty good as a piece of garden 'architecture' out of season...
Such things go for £25 in some garden centres...

To keep the uprights under control, use a cardboard box with holes cut in the top to stand them in. You have a box with a circle of holes with an upright jammed into each. It makes the whole thing easier to control.